I'm not familiar with 'TeleCheck' but I can relate on the embarrassment level.
One time, probably some 25-30 years ago, I had gone to CSAA to get some traveler's checks just before going on a vacation.
If you had CSAA (which we did - auto insurance and the card), you could write a check for the travelers checks (this was before debit cards were an automatic issue with checking accounts).
Ok, no problemo. So I write it out for $2,500 worth of travelers checks and, as I was waiting, with quite a few other people in the room, she came back and declared, much too loudly I might add, that the check was not good.
Needless to say, I was PROFOUNDLY embarrassed that everybody in the room had to hear that. But the reality was that there was much more in our account than the measly $2,500 I was writing.
I had to end up calling the bank and having her talk to somebody who said the check was good and when she was called the first time (back then people called the bank to clear a check) was wrong. I was then given the phone back and the person at the bank was pretty much like 'hahaha oh well - just a mistake'. Seriously - she laughed!!
Imagine my ire because, um, really? No apology?? I don't ask for anything from anybody but I DO know when an apology is in order. Anyway, the travelers checks were issued and it ended up fine but I did complain that when the bank was called the first time she made a massive error and declined the check and didn't even apologize.
I would have apologized PROFUSELY if I did that sort of thing to somebody. I could very easily get over the mistake if the person had apologized. THAT was the part of it that really made me angry, not the error. We all (well, most of us. ha!) make mistakes. It's how you handle the mistake that matters the most.